Area Forecast Discussion
Issued by NWS Boise, ID

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FXUS65 KBOI 250314

Area Forecast Discussion
National Weather Service Boise ID
914 PM MDT Mon Oct 24 2016

.DISCUSSION...Showers and thunderstorms that crossed southeast
Oregon and southwest Idaho this afternoon/evening have pushed into
eastern ID as of 03Z. Area will see a brief break before a second
round of showers develops early Tuesday morning. Focus for shower
development will be ahead of a weak front that pushes into
southeast Oregon by 12Z. Ahead of the front, the southwest Idaho
mountains will keep a chance of showers overnight with orographic
lift and weak elevated instability providing the support. Have
updated the forecast to lower precip chances in the valleys for
the remainder of the night.


.AVIATION...VFR. SCT-BKN mid and high level clouds. Isolated rain
showers, mainly over higher terrain, with local mountain obscuration
and low VFR ceilings. Until 05Z isolated thunderstorms over the
Magic Valley with brief heavy rain and gusty winds. Surface winds
east to south 12 knots or less, except gusty near showers and
thunderstorms. Winds aloft southwesterly 30-40 knots up through 10K
feet MSL.


SHORT TERM...Tonight through Wednesday...A strong area of low
pressure parked off the Washington and Oregon coast continues to
send a broad swath of moisture over the region. The cold front
associated with the low is finally making eastward progress across
Washington and Oregon. This front is expected to stall over southeast
Oregon and southwest Idaho this evening and overnight. Showers and
isolated thunderstorms have developed and will continue to develop
along and just ahead of the front. These showers and isolated
thunderstorms will be most prevalent during the evening hours
while weak instability lasts. While the best chance for thunder
exists over the higher terrain, generally south of the Snake River
Plain, some strikes and rumbles may make their way northward
across the valley into the central mountains this evening.

Near term models are in good agreement that the front will stall
and weaken over the area tomorrow as the Pacific low tracks north
and mid and upper-level ridging attempts to build over the
intermountain west. This remnant front will serve as the impetus
for shower activity tomorrow into tomorrow evening before lifting
northward as a resurgent warm front ahead of the next Pacific low
tomorrow night into Wednesday. As the front lifts northward the
area will see a drying and warming trend for the remainder of the
day Wednesday with shower activity confined to northern areas and
higher terrain.

LONG TERM...Wednesday night through Saturday...A moist
southwesterly flow aloft will keep a threat of showers over
southeast Oregon and Idaho`s West Central Mountains through
Thursday. As early as Friday morning, a stronger shortwave will
pull out of the southwest and transition across the region,
bringing widespread showers to the whole region. This shortwave
looks to have enough jet support and instability to produce
thunderstorms Friday, but have left this aspect out of the
forecast for now as there are still a few discrepancies between
the models that need to be worked out. Precipitation totals with
any initiated convection could become a concern over the
mountains. Saturday will continue the trend of moist
southwesterly flow aloft, with a threat of showers forecasted
over much of the region. Temperatures will remain above the
seasonal norm through the period under this pattern. Expecting
snow levels between 8500-9500 ft.

Saturday night through Monday...An active pattern through this
period with an upper low sitting off the California coastline
Saturday night advecting moisture into our area with the
southwesterly flow aloft. Chances of precipitation are greatest for
the higher elevations in both SE Oregon and SW Idaho through Sunday
evening. This low slowly tracks northeastward Sunday into early
Monday morning increasing chances of precipitation for valley
locations. Temperatures remain above normal during this time





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